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Finding the Fourth Proportional to 613.68, 920.72 and 409.05

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Solution

The fourth proportional to 613.68, 920.72 and 409.05 is: 613.71

Step by Step Solution

  1. Step 1: Write the proportion equation
    613.68 : 920.72 = 409.05 : x
  2. Step 2: Convert to fraction form
    613.68/920.72 = 409.05/x
  3. Step 3: Cross multiply
    613.68x = 920.72 × 409.05
  4. Step 4: Simplify right side
    613.68x = 376,620.52
  5. Step 5: Solve for x
    x = 376,620.52/613.68
  6. Step 6: Final answer
    x = 613.71

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Why These Related Problems?

These problems maintain the same ratio (1.50) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.